I had some bloods on Tuesday. The following day the GP called to tell me my egfr had dropped, in her view, significantly, particularly compared to baseline, and my creatinine has gone up, both are out of range. She's told me not to worry and is repeating bloods next week.

What I've noticed is many of my other blood results have noticeably changed in some way but are within range e.g. My serum sodium has dropped and my serum potassium has risen. I don't have any new symptoms and don't drink anymore or less than usual. My ferritin is also low but in the UK they've changed the threshold and my results don't warrant treatment anymore. 

By way of background, in September 2024 I had a lower anterior resection - essentially the majority of my rectum removed, and a temporary ileostomy / stoma which wad reversed in December 2024. Following this I've had ongoing symptoms including lethargy, struggling to wake up in the morning, brain fog, weight loss / inability to put on weight despite eating more than ever, salt craving, palpitations to name the main ones.

The GP said the results indicate there's an issue with my kidneys but there was nothing obvious that came up from her questions e.g. Headaches, increased/decreased urination, taking certain medications etc.

Medical history aside, has anybody experienced anything similar in terms of the blood results, and has a diagnosis of some sort? Clearly I'm concerned, although I'm hopeful it's just an anomalie, but as I've had many bloods over the last few years that have never shown these results it is a worry.

I really appreciate any thoughts. 

GP called day after blood test concerned about results